Business Combinations H&N Acquisition - Fair Value of Assets and Liabilities (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended					4 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Nov. 01, 2017	Aug. 31, 2017
Business Acquisition [Line Items]
Goodwill		$ 45,589	$ 40,686				$ 45,589	$ 45,589	$ 40,686
Successor [Member]
Business Acquisition [Line Items]
Business Combination, Fair Value Step-Up Of Acquired Inventory, Amount recognized in Cost of Goods sold	$ 360		134	$ 109	$ 682	$ 703	1,109	1,469	1,628
Goodwill		45,589	$ 40,686				$ 45,589	$ 45,589	40,686		$ 45,105
Successor [Member] | H&N Business [Member]
Business Acquisition [Line Items]
Business Combination, Fair Value Step-Up Of Acquired Inventory, Amount recognized in Cost of Goods sold		$ 35							$ 65
Cash and Equivalents										$ 16
Accounts and Notes Receivable										144
Inventories										304
Property, plant and equipment										489
Goodwill										732
Other intangible assets										435
Other current and non-current assets										14
Total assets										2,134
Accounts payable and other accrued liabilities										72
Deferred Tax Liabilities										92
Total Liabilities										164
Fair value of net assets										$ 1,970